In this ShEEP grant, we request funds to purchase a preclinical in vivo imaging system from Perkin Elmer for installation in the phenotype core of the Musculoskeletal Disease Center of VA Loma Linda Healthcare System (VALLHCS). The IVIS SpectrumCT from Perkin Elmer is an integrated premier optical imaging and low-dose microCT that enables simultaneous molecular and anatomical longitudinal studies, providing researchers with essential insights into complex biological systems in small animal models. The constant horizontal gantry motion and the flat panel detector provide outstanding performance for low-dose imaging and automated optical and microCT integration. The stable revolving animal platform rotates 360o enabling acquisition of full 3D data. Another feature of this system is that multiple animals can be scanned simultaneously while maintaining an average dose per scan at 1.3 Gy, with scanning and reconstruction time of less than a minute. The system also allows operation of optical and microCT modalities independently. The IVIS SpectrumCT allows for true topographic surface mapping of the animal and the included workflow and imaging wizard features facilitate procedures for 3D tomography and 2D screening modes in bioluminescence, fluorescence and Cerenkov luminescence. This new instrument will be used by a number of investigators at the VALLHCS to perform in vivo small animal imaging work. The applications include but are not limited to experiments proposed in various funded studies that will benefit immensely by the availability of this in vivo optical imaging system. The software that comes with the system allows automated and precise quantitation of the various fluorescent signals employed. The system also allows for obtaining high quality images for data documentation and publication. A number of VA, DOD and NIH funded investigators at this VA Medical Center including Drs. Mohan, Lau, Rundle, Qin, Dong, Xing, Li and Edderkaoui require this equipment to perform studies related to their funded grant applications. Currently, no in vivo imaging system for small animals is available for research use at VALLHCS. The requested instrument is needed for successful completion of funded studies that are relevant to the pathogenesis and treatment of osteoporosis, osteoarthritis and hearing loss, diseases that are target areas of the VA research mission.